Free flowing alkyl aryl sulfonate detergent compositions



FREE FLOWING ALKYL ARYL SULFONATE DETERGENT COMPOSITIONS Louis H. Libby, Newton Highlands, and Lloyd F. Henderson, Readmg, Mass., assignors to Lever Brothers Company, Cambridge, Mass, a corporation of Maine No Drawing. Application September 29, 1949 Serial No. 118,715

6 Claims. (Cl. 252-137) This invention relates to detergent compositions comprising guanidine alkyl aryl sulfonate, and especially to combinations of sodium alkyl aryl sulfonate and'guanidine alkyl aryl sulfonate, which are relatively nonhygroscopic and when in powdered form are free-flowing and non-sticky, and do not cake even when exposed to an atmosphere of relatively high humidity at room temperature.

The alkali metal alkyl aryl sulfonates comprise one of the principal types of the so-called non-soap surface active agents and possess detergent, dispersing, wetting and emulsifying properties. The alkyl aryl sulfonates are of commercial interest because they can be derived from petroleum sources and are of relatively low cost and readily available. They are marketed by numerous companies under many trademarks and trade names. Generally, the sodium salt is sold and used commercially. it is available in the so-called salt-free state or mixed with various other salts or diluents.

The sodium alkyl aryl sulfonates have found particular favor for specialized uses; particularly in the textile. field and in many industrial applications. Their use in the general household detergent field involves difiiculties because they are hygroscopic and when exposed to the atmospheric humidity that normally prevails in many climates they absorb moisture from the air and become lumpy or caked and consequently do not pour freely from the carton.

In accordance with the invention, it has been found that if the alkyl aryl sulfonicacid is neutralized with guanidine or a guanidine base, such as commercially available guanidine carbonate, the resulting guanidine alkyl aryl sulfonate may be drum or spray dried to triable, non-sticky, free-flowing powder; and this is eminently suited for formulation into an excellent general household detergent powder that is free-flowing.

The objects achieved in accordance with the invention include a provision of an alkyl aryl sulfonate salt which is non-sticky and free-flowing in powder form and retains these properties even on prolonged exposure to an atmosphere of relatively high humidity at room temperature; the provision of a composite alkyl aryl sulfonate containing both the guanidine sulfonate and the sodium sulfonate which is non-sticky and free-flowing when in powder form and retains these properties even on prolonged exposure to an atmosphere of relatively high humidity at room temperature; and other objects which will be apparent as details or embodiments of the invention are set forth hereinafter.

Guanidine alkyl aryl sulfonate may be typified by the following formula:

tates atent" ice Sodium alkyl aryl sulfonate may be typified by the following formula:

none SOs.Na

The aryl-alkane hydrocarbon material intermediate is commercially available, and it may be prepared in accordance with known methods. Two general methods are known. In one method the alkane hydrocarbon is chlorinated and then condensed with the aryl hydrocarbon using aluminum chloride as a catalyst. In another method an olefin is polymerized and the-polyolefin condensed with the aryl hydrocarbon using hydrogen fluoride as a catalyst. It is sulfonated in accordance with known methods preferably to introduce one sulfonic group into the aryl ring, and this group will be in the ortho or para position, with the latter type compound predominating, in accordance with known principles. Sulfuric acid or oleum is used following well established practices. Generally, an excess of the sulfonating agent is used. After the sulfonating reaction, excess reactants may be removed is desired. However, for many technical uses, the reaction mixture may be converted directly to the corresponding salt, by treatment with the appropriate neutralizing agent'or agents. There may be some disulfonate, or other polysulfonate present, but this is preferably kept to a minimum. If desired, such polysulfonates may be removed from the sulfonation reaction mixture, prior to neutralization to form the desired detergent sulfonate. However, the presence of a relatively small proportion of the neutralized polysulfonates in the final detergent composition is not particularly disadvantageous; and for reasons of economy, procedures which require separation of vpolysulfates are to be avoided.

In a typical operation, the sulfonation reaction mixture is washed, diluted with water, and then neutralized with the appropriate material, e. g., guanidine carbonate, to give the desired salt; the resulting paste contains the guanidine alkyl aryl sulfonate. It may be drum or spray dried to a friable, non-sticky, free-flowing powder. This material may be formulated into an excellent general household detergent powder. The guanidine alkyl aryl sulfonate may be combined with sodium alkyl aryl sulfonate to give a material which may be spray dried or drum dried and ground to form a non-sticky free-flowing powder.

The guanidine alkyl aryl sulfonate may be prepared in concentrated form, and then mixed with a paste of sodium alkyl aryl sulfonate, and dried together. Or, alternatively, the alkyl aryl sulfonic acid may be treated with a mixture, of guanidine and sodium neutralizing agents such that, for instance, 20% of a total acid (equivalent basis) is converted to the guanidine salt and 80% is converted to the sodium salt. A mixture of the two bases may be added or they may be added one after the other. The

" resulting paste may be spray dried or drum dried and ground if desired to a friable, non-sticky, free-flowing powder.

For reasons of economy, the guanidine component will be kept at a minimum. In order that the composition will form a powder which is non-sticky and free-flowing, at least 7.5% (equivalent weight basis) of the alkyl aryl sulfonate salt should be the guanidine salt, and the balance is an alkali metal alkyl aryl sulfonate, generally the sodium salt; there is no operative upper limit forthis V 3 purpose, since the pure guanidine alkyl aryl sulfonate has these properties. Where some caking is not objectionable, the guanidine sulfonate agent may be as low as 5% (equivalent weight basis) generally the preferred guanidine sulfonate agent will be in the range of 7.5% to 30%, or even up to 50% (equivalent weight basis).

The guanidine alkyl aryl sulfonates or a-mixture thereof with sodium alkyl aryl sulfonate, may be used with the various builders and with inactive diluents. The first term is well known in -the soap industry and is used herein with the same meaning. Examples of the general class of builders and diluents are sodium sulfate, magnesium sulfate, guanidine sulfate, sodium chloride, and any of the alkali metal phosphates, silicates, borates and carbonates. The presence of phosphates and in particular polyphosphates, such as tetrasodiurn pyrophosphate and pentasodium tripolyphosphate, are especially advantageous. Some of these compounds exert more of a building action than others, and the exact line between a compound which is entirely inactive and can be characterized as a diluent and a compound which acts as a builder, is not precise.

In view of the explanation given herein and the illustrative examples, it is believed that one skilled in the art will understand the scope of the expression inactive diluent and builder.

The inactive diluents and the builders may be neutral, alkaline or acid salts. It is to be noted in particular that the acid phosphates may be employed and excellent detergent results have been obtained in compositions which in solution have a pH value below 7 as well as those having relatively higher pH values ranging from 7 to 12. The inactive diluents and builders may include other materials, such as starch and various synthetic materials, such as polyethylene glycols, polyvinyl alcohols, carboxymethyl cellulose, and other natural or synthetic materials which are soluble or dispersible :in water.

In a detergent composition, the proportion of the alkyl aryl sulfonate may vary, generally not less than 10% and not more than 50%, 1 5% to 35% being the usual range. At lease 7.5% of the alkyl aryl sulfonate content is guanidine alkyl aryl sulfonate as explained. The balance of the composition (other than alkyl aryl sulfonate) may be diluents and builders, soap, etc.

It will be obvious that the compositions may be made by any of the known methods of producing products in powdered form, such as by drum drying, spray drying, grinding, etc., and that the compositions may be varied, as is well known by those skilled in the art, to include such other materials as prefume, coloring material,

fluorescent "compounds, anti-oxidants, and any other material which does not detract from the essential detergent action.

The expression consisting essentially of as used herein, is intended to mean that the ingredients recited are the essential ingredients, and such expression is not intended to exclude from the composition other ingredients in such amounts as would not render the composition unsuitable for detergent purposes.

EXAMPLE 1 (a) A fairly large batch of phenyl alkane is obtained from the commercial market, or prepared by polymeriz ing propylene, in presence of an excess of propylene dimer and a phosphoric acid catalyst, to form a liquid mixture of acyclic C1245 branched-chain olefins which is resistant to degradation under alkylating conditions; separating from this mixture a fraction havingan 1R factor (ratio of corrected optical density at about 10.35 mu to corrected optical density at about 11.23 mu) greater than 1 and a boiling range of 300-600 F.'; condensing with benzene at 50-100 F. in presence of a fluoride catalyst, and separating a monophenyl alkan'e fraction of boiling range 350-650 F.

fuming sulfuric acid in a proportion of 2 to 5 mols of 4 per mol of the aryl-alkane, at a temperature of 10 to 50 C. for 3 to 5 hours. The reaction mixture is then cooled and washed. The product analyzes 67.1% alkyl aryl sulfonic acid, 2.01% nonacidified organic matter, 11.06% sulfuric acid, and the remainder water or inert impurities.

(b) A 500 gram portion of this reaction mixture is treated with 193.84 grams of guanidine carbonate (thec retical amount for neutralizing both the sulfuric acid and the sulfonic acid material) in the presence of 1000 grams of Water. The resulting reaction mixture is then drum dried and ground to apowder all of which passes through a ZO-mesh screen (U. S. sieve series). This material is referred to hereinafter .as Example 1(b) material.

(c) Another 500 gram portion of the above 1(a) material is treated With86.l4 grams of sodium hydroxide (the theoretical amount to. neutralize both the sulfuric and the sulfonic acids present) in the presence of 1000 grams of water. The resulting material is subjected to the drying and grinding treatment as in 1(b), and the powder (a) The alkyl aryl sulfuric acid used in this example is the same as that described in Example 1(a).

(b) 500 grams of the above 2(a) material is treated with 38.77 grams of guanidine carbonate (20% of the amount theoretically required to neutralize the sulfuric and sulfonic acids present) and 43.07 grams of sodium hydroxide (80% of the theoretical amount required to neutralize the sulfuric and sulfonic acids present) in the pres ence of 1000 grams of water. The reaction product is dried and ground as described in Example 1(1)) above; and the resulting product is referred to hereinafter as the Example 2(b) material.

H ygroscopicity test TABLE 1 Product, of Example N o 1(1)) 1(0) 2(6) Weight percent Hi0 absorbed at exposure time of:

2. 8 6. 1 1. 6 '5. 8 i s. a 5. 4 7. 4 10. 6 1 6. 6

1 Calculated by interpolation or extrapolation-other values measured.

The sodium alkyl sulfon'ated material 1(0) shows a very high water "absorption, and even after the exposure time of 1 day thispowder became 'caked and sticky. On the other hand, the guanidine'alkyl arylsulfonate powder 1(b) showeda much lower water absorption, and was free-flowing and non-sticky even after 5 days. The composite .guanidine sodium alkyl aryl sulfonated powder 2(1)) shows a lower water absorption than either the 'g'uanidine alkyl aryl sulfonate 1(b) or the sodium alkyl aryl sulfonate l(c); and this powder was free-flowing and non-sticky even after an exposure time of 4 days. This data illustrates the marked superiority of the guanidine alkyl aryl sulfonate and especially the composite guanidine-sodium alkyl aryl sulfonate as a free-flowing non-sticky powder material which retains this characteristic even on prolonged exposure to relative high humidity at room temperature.

aaea'me the products were tested by measuringwater absbrption, this is not always a true index of their freeflowing properties. Thus sample 1(b) at 5 days had 7.4% moisture and was free-flowing, whereas sample 1(0) at 1 day had 6.1% moisture and was sticky. Not only is the amount of moisture significant, but also the fact that the sodium salt tends to dissolve more readily in the available moisture and thus to become more sticky.

Further results are shown in the following table in which the compositions are identical except as shown:

Sodium alkyl aryl sulfonate 27.5%. Guanidine alkyl aryl sulfonate 0% 7.5%. Tetrasodium pyrophosphate 25%. Sodium sulfate 3 30%. Miscellaneous 10%. Water absorbed on exposure to 80% v .3 14.9%.

relative humidity for 11 days at room temperature. Condition of powder Sticky and Not sticky caked-not freefree-flowflowing. I ing.

The effect of variations on the hygroscopic and free flowing properties of the composition can be seen from the following table. In the composition listed therein, the-guanidine alkyl aryl sulfonate and sodium alkyl aryl sulfonate are made separately in accordance with the examples described heretofore, and the pastes mixed and dried. They were subjected to the hygroscopicity test described heretofore. in all instances the amount of the active component, i. e., the alkyl aryl sulfonates,

was the same, namely 75% to 80%.

Percent Water Composition of Active Component Ab- Condition of Powsorbed der After 14 Days After 14 Days 100% Guanidine Alkyl Aryl sulfonate..- 17.0 Free Flowing. 100% Sodium Alkyl Aryl Snlionate 11.7 Caked, Sticky and Not Free Flow- 95% Sodium Alkyl Aryl Sulfonate ggg s fi g gli i ig i s ff 10.7 Somewhat Caked.

0 o um y u one. e.

10%Guanidlne A1kylArylSulfonate 7 Free Fmwmg- 80% Sodium Alkyl Aryl Sulfonate l0 0 D o 20% Guanidiue Alkyl Aryl Sultanate...

70% Sodium Alkyl Aryl Sulfonate 7 6 D0 30% Guanidine Alkyl Aryl Sulfonat 50% Sodium Alkyl Aryl Sulionate 4 3 Do 50% Guanidine Alkyl Aryl Sulfonate It will be observed that the amount of moisture absorbeddoes not always hear a direct relation with the sticky or free-flowing properties of the product; thus the guanidine alkyl aryl sulfonate absorbs more water than the sodium alkyl aryl sulfonate but nevertheless was free flowing. The mixtures absorbed less water and are free flowing. j. I In' addition to preparing the composition by forming guanidine alkyl aryl sulfonate through the neutralization of the alkyl aryl sulfonic acid with a guanidine base, the guanidine alkyl aryl sulfonate can be formed through metathesis of ingredients in the composition. As illustrative of this embodiment of the invention 160 grams of sodium alkyl aryl sulfonate paste containing 48% of the sulfonate, as prepared in accordance with Example 1(c), is mixed with 40 grams of guanidine sulfate dissolved in water. The ingredients are stirred and heated for 20 minutes at a temperature of 90 to 100 C. and the product is drum dried. After 14 days the powder is free flowing. .In addition to utilizing guanidine sulfate, the guanidine alkyl aryl sulfonate can be made from the sodium alkyl aryl sulfonate by radical interchange reactions utilizing guanidine phosphate, guanidine carbonate and other guanidine salts. Any reference to the composition containing guanidine alkyl aryl sulfonate includes the composition made by any of the various methods described.

As indicative of the detergent properties of the composition of the invention, dishwas hing'tests were'run in which plates were uniformly smeared with-a standardcomposition and the plates were-all washed under identical and standardized conditions. In all cases, the alkyl aryl sulfonate was present in the same amount, namely approximately 60%, and the balance was fillers and diluents. The compositions were the same except for the changes indicated in the table. Inasmuch as the, results are comparative, it is unnecessary to describe the details of the tests in order to understand the superiority of the compo.- sitions made in accordance with the invention. The results are as follows:

Number of Plates Washed Product p 1 A .02t3% cone. .0375% cone.

in 300 in 300 p. p. m p. p. m. HzQat Hioat 2 F 1 .3

Sodium alkyl aryl su1fonate '40. 46 Guanidiue alkyl aryl sulfonate 26 56 Mixture:

20% guanidine alkyl aryl sulfonate..-- sodium alkyl aryl sulfonate The results in the above table indicate that the dishwashing capacity of the guanidine alkyl aryl sulfonate is much greater than a straight line function of its concentration in the dishwashing water, whereas the dishwashing capacity of sodium alkyl, aryl sulfonate isless thana straight line function of its concentration idthe dishwashing solution. The results also showjthat the presence of the guanidine alkyl aryl sulfonate are minor proportion with sodium alkyl aryl sulfonate imparts the characteristic properties of the former to the latter, since the dishwashing capacity of the combination is greater than a straight line function of the-concentration of the combination product in the dishwashing solution. It is also to be noted that the combination of the guanidine and sodium alkyl aryl sulfonates showed better dishwashing capacity than is exhibited by the sodiumalkylaryl sulfonate or the guanidine alkyl aryl sulfonate when considered separately. I

As further showingthe superiority of the composition containing guanidine alkyl aryl sulfonate in a mixture with a pyrophosphate using soft water, the following table is included:

GIG!

Tetrasodium pyrophosphate Sodium sulfate where R is an alkyl radical having from 6 to about 18 carbon atoms and an amount which in the absence of the guanidine alkyl benzene sulfonate would impart to .the'composition a deliquescent tendency, up to 92.5% of an alkali metal alkyl benzene sulfonate having the general formula I a BOaM where R is an alkyl radical having from 6 to about 18 carbonatoms and M is an alkali metal cation.

2. A composition in accordance with claim 1 in which the alkyl radical is a polypropylene radical.

3. A free'fiowing detergent composition consisting es-' sentially of at least 7.5% of a guanidine alkyl benzene sulfonate having the general formula where R is an alkyl radical having from 6 to about 18 carbon atoms, an amount which in the absence of the guanidine alkyl benzene sulfonate would impart to the composition a deliquescent tendency, up to 92.5 of an alkali metal alkyl benzene sulfonate having the general formula where R is an alkyl radical having from 6 to about '18 carbon atoms and M is an alkali metal cation, diluents and builders.

4. A free-flowing detergent composition consisting essentially of at least 7.5% of a guanidine alkyl benzene s'ulfonate having the general formula where R is an alkyl radical having from 6'to about 18 carbon atoms and an amount which in the absence of the guanidine alkyl benzene sulfonate would impart to the composition a deliquescent tendency, up to 92.5% of a sodium alkyl benzene sulfonate having the general 'formulw SOaNa where R is an alkyl radical having from 6 to about 18 carbon atoms.

SI A free-flowing detergent composition consisting essentially of from to 50% of a mixture of at least 7.5

of a guanidine'alkyl benzene sulfonate having the general formula where R is an alkyl radical having from 6 to about 18 carbon atoms, and an amount which in the absence of the guanidine alkyl benzene sulfonate would impart to the composition a deliquescent tendency, up to 92.5% of an alkali metal alkyl benzene sulfonate having the general formula R SOsM where R is an alkyl radical having from 6 to about 18 carbon atoms and an amount which in the absence of the guanidine alkyl benzene sulfonate would impart to the composition a deliquescent tendency, up to 92.5 of an alkali metal alkyl benzene sulfonate having the general formula R SOaM where R is an alkyl radical having from 6 to about 18 carbon atoms and M is an alkali metal cation, and from to 50% of diluents and builders, including at least 25% of tetrasodium pyrophosphate. i

References Cited in the file of this patent UNITED STATES PATENTS 2,223,935 Daniels Dec. 3, 1940 2,298,651 Samaras et al. Oct. 13, 1942 2,314,255 Toone Mar. 16, 1943 2,374,187 Flett Apr. 24, 1945 2,433,394 Paden et a1 Dec. 30, 1947 2,444,837 MacMahon July 6, 1948 2,535,972 Vitalis Dec. 26, 1950 

1. A FREE-FLOWING DETERGENT COMPOSITION CONSISTING ESSENTIALLY OF AT LEAST 7.5% OF A GUANIDINE ALKYL BENZENE SULFONATE HAVING THE GENERAL FORMULA 